Spark-gap and muffler therefor.



2 SHEETS-SHEET l.

4 v. a f .Anz ..2 ow. IIIIIAIIILA PATBNTED OCT. 23, 1906. A. E. HARRISON & C. M. HASLETT. SPARK GAP AND MUFFLER THBRBFOR.

ki Il.' III III v af APPLIOATION FILED SEPT. 28. 1905.

W/ TNE SSE S: v

No. 834,054. PATENTED OCT. 23, 1906. A. E. HARRISON & G. M. HASLBTT. SPARK GAP AND MUFFLER THBREPOR.

APPLICATION FILED SEPT. 26. 1905.

2 SHEETS-SHEET 2.

. ril 1 .v

...MHP

y w/TNESSES:

A TTORNE Y S UNITED sTATns rfnTnNT oFF-ICE.

AARON E. HARRISON.,l 0F NEW YORK, N. Y., AND CROWELL M. HASLETT.. OF JERSEY CITY, NEW JERSEY. l

SPARK-GAP AND MUFFLER THEREFOR.

No. 834,054.y

Specification of Letters Patent.

Application filed September 26, 1905. Serial No. 280,180.

- United States, have inventeda new and Improved Spark-Gap and Muffler Therefor, of which the following is a full, clear, and exact description.

Our invention relates to spark-ga s of the kind used in wireless telcgraphy an in relations analogous thereto, our more particular object being toprovide an improved form of muffler for inclosing the spark-gap so as to reduce to a mimimum the annoyance caused by sound proceeding therefrom.

It will be understood that in wireless telegraphy the spark-gap is very noisy, so much so that if the sounds are not properly muffled they become a considerable nuisance to people in the immediate vicinity. To telegraph operators and other employees the sounds in f uestion are exceedingl undesirable, producing, as they do, pain l sensationsin the ears and even temporarily disqualifying the ears for efficient service in detecting delicate noise made in the receiving instrument-that is to say, a telegraph operator whose ears have been subjected to the influence of the loud sounds in question is unable to hear the delicate sounds of the telephone-receiver commonly used in wireless tele raphy. Often in ordi-nary work it is desirable for theoperator to send a few words at a time and then listen to the sounds of his receiver. His ears are thus alternately' subjected to such extremes of sound that their sensitiveness is not at its maximum when he is listening to the sounds of the receiver. Our purpose, therefore, is to so completely muffle the sounds from the spark-gap as to avoid the difficulties above mentioned.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a vertical central section showing a s ark-gap and our improved muffler as applic thereto, and Fig. 2 is a horizontal section through the same upon the line 2 2 of Fig. 1 looking in the direction of the arrow.

Fig. 3 is a vertical section through a form of muffler used 1n connectlon w1th a removable Patented oct. 2s, 1906.

s ark-gap, this figure also showing the mufer-drum common to both types of muffler. Fig. 4 is a horizontal section upon the line 4 4 oflFig. 3 looking in the direction of the arrow and showing the perforated annular walls of the. muffler-drum and the fireproof filling intermediate of these walls, and Fig. 5 is a section upon the line 5 5 of Fig. 3 lookin in the direction of the arrow and showing t e bottom part of the removable spark-gap.

Integral with the base 3 is an outer shell 4 and an inner shell 5. These shells are ofannular form and concentric to cach other. The inner shell 5 encircles a cylindrical chamber 6. v Intermediate of the two shells in 'question is an annular channel 7, ada ted to serve as a sound-proof chamber or to e filled with a'substance such as mineral wool, sawdust, asbestos, or the like for the pur ose of destroying sounds tending to ass tfirough the cham er. The base 3 an the shells 4 and 5 are made, preferably, of carthenwarc, porcelain, fire-clay, or cement, the outer shell 4 and the exterior of the base 3 being glazed at 4a and preferably harder than the inner shell 5. A lid 8 is snnilarly glazed at 8a and is provided with annular ribs 8b 8, projecting slightly downward'and so disposed that the annular rib 8b neatly encircles the shell 4, while the annular rib 8c closel encircles the inner shell 5, thus effectively reaking joint as between the lid 8 and the shells 4 and 5. The mufficr is connected with an air-outlet pipe 9 and an air-inlet pipe 10, disposed in threaded apertures 11 12. The purpose of these pipes is to allow a circulation of air through the muffler, thereby keeping the spark-gap as cool as practicable. The inletp ipe 10 may be connected with a supply of air under pressure. As the airv after exposure to the spark-gap becomes partially conducting it will be displaced by fresh air, and the ventilation afforded by the invention described promotes this purpose. l

The 11d 8 is rovided with a central aperture 13, throng which a bushing 14 projects a slight distance into the muffler. This bushing is provided with a shoulderl 15, which engages the upper surface of the lid and serves as a limiting-stop for the bushing.

IOO

Mounted within the bushing 14, which is made of fireproof insulating material-- preferably glazed porcelain-is a metallic tube 16. The upper endof this tube .is threaded and is iitted with a larger tube 17, the lower end of the latter being threaded internally for the purpose. Encircled by the larger tube 17 is a quantity of mineral wool 18 or any desired ireproof material. A cap 19 is threaded internally and litted upon the tube 17. The metallic electrode or stem 2() is threaded and passes through the mineral wool 18 into thc tube 16. A nut 21 is screwed upon the lower end of the tube 16, and thus encircles the electrode 20. This electrode 20 terminates in a hemispherical end 22. Another hemispherical end 22 is turned on an electrode or stem 23, which may be molded rigidly into the bottom of the muffler, as shown. The purpose of the sleeve 16 is to afford a threaded passage for the electrode 20. The filling 18 prevents the escape of sound, while allowing the electrode to be adjusted. The electrode 20 is removed by unscrewing it from the threaded tube 16.

In the form shown in Figs. 3, 4, and 5 the lid 24 covers the central chamber 25 and the -inner and outer concentric walls 4 and 5.

Two disks 26 27 are connected together by tie-rods 28, and disposed centrally within these disks are spark-terminals 29. The electric conductors are led in through holes 3() and 31 and connect with these terminals, so as to energize the same, the method of connection being immaterial. Upon removing the lid 24 the disks 26 and 27, together with the tie-rods 28 and the conductors 29, are removable as a unit. This entire removable member we designate as a removable spark-gap. The action` of the muffler shown in the lower art ofl Fig. 3 is substantially the same as t at shown in Figs. 1 and 2. The upper end of the outlet-pipe 9 is threaded and fitted into a comparatively large disk 32, surmounted by another disk 33, the two disks being connected together by means of concentric cylinders 34, 35, 36, and 37, the latter being rovided with holes 38, 39, and 40, staggere in relation to each other, as indicated in Figs. 3 and 4. Intermediate of the concentric cylinders 34, 35,A

36, and 37 are annular portions 41 of mineral wool, asbestos, or other ireproof material.

This substance is loosely disposed, so as to allow the heated air to pass outwardly from the inner cylinder 34, and yet, owing to the staggering of the holes and the deadening quality of the substances, little or no sound can make its-escape. The cylinders 34, 35, 36, and 37are let into the disks 32 and 33, together therewith constituting a member which we designate as the muffler-drum.

We find that by making the inner shell 5 comparatively porous it is rendered effective in deadening the sound-vibration.- When a spark-gap is placed within the muffler and is active, the sounds are scarcely audible, so effectively are they muilled.

llaving thus described our invention, W( claim as new and desirel to secure by Letters Patent- 1. In a mulller, the combination of a member provided with limer and outer shells, and further provided with means whercb a spark-gap maybe maintained within saidrinner shell, and a lid engaging said inner and vouter shells and provided with portions for breaking joints between said lid and said inner and outer shells. i

2. In a muffler, the combination of an inner shell of porous material, an outer shell encircling the same, and means for mounting spark-terminals within said inner shell.

3. In an apparatus of the character described, the combination of a base portion provided with inner and outer shells integral therewith and concentric to each other, a lid provided with annular members for fitting said inner and outer shells so as to break joints therebetween, and spark-terminals for maintaining a static discharge Within said inner shell.

4. In an apparatus of the character described, the combination of a hollow member lor containing a spark-gap, an outlet-pipe connected with said hollow member, a mufling-drum connected with said outlet-pipe, and means for supplying air into lsaid hollow member.

5. In an apparatus of the character described, the combination of a hollow member for containing a spark-gap, means for admitting air thereinto, and a mufIling-drum connected with said member and receiving therefrom the air heated by the spark-gap, said muflling-drum being provided with means IOO for discharging said heated air while preventing the sounds from escaping.

6. In an apparatus ol the character described, the combination of a hollow member, an outlet-pipe connected therewith, a disk mounted upon said outlet-pipe, a plurality ol concentric cylinders connected with said disk and provided with holes staggered in relation to each other, another disk mounted upon said concentric c linders, and means for admitting air toy sai .hollow member. 7. In an apparatus of the character described, the combination of a receptacle provided with a spark-gap, and a muffler-drum separate from said receptacle and connected therewith.

8. In an apparatus of the character described, the combination of a hollow member, a spark-gap mounted therein, and a muffler-drum connected with said hollow member, said muffler-drum being provided with a plurality of outlets staggered relatively to each other.

9. In an apparatus of the character de- IIO scribed, the combination of a hollow member, a spark-gap mounted therein, a mulerdrum communicating with said hollow member, said muffler-drum having a plurality of walls provided with apertures, and fillings mounted intermediate of said walls for the purpose of suppressing sounds.

10. In a muffler for spark-gaps, the combination of a sound-proof receptacle for containing a spark-gap, a muffler-drum connected with said receptacle and provided with a .plurality of outlets, and means for forcing a cooling medium through said receptacle and into said muffler-drum.

11. In an apparatus of the character described, the combination of a hollow member, means for conducting an air-current therefrom, a sparkap mounted within said hollow member, an a mufller-drum connected with said hollow member and provided with concentric walls, said walls having apertures staggered relatively to each other for the purpose of depressing sounds from said hollow member.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

AARON. E. HARRISON. CROWELL M. HASLETT. Witnesses:

WALTON HARmsoN, EVERARD B. MARSHALL. 

